Good bookshelf speaker?

KEF LS50. I own Magico speakers and the LS50 monitors blew me away when I heard them...left the audio store with a pair. Lots of flagship technology built into this speaker. Only ported speakers I have heard that don't have the chuffing and bloat I usually hear. I think the KEF LS50 speakers, especially paired with a decent (fast) sub, can compete against $5,000-$10,000 systems. I believe 10 years from now I will look back and wish I had bought an extra pair as collectors item or as backup.

Do you need front- or rear-ported?

I had one of those amps myself. My recommendation would be to stay away from anything bright sounding and/or with a metal tweeter. Looking at your list, I would probably say the ProAc is the best match.

The reference 3a speakers are very very special. MM DE Capo's especially. One you did not list is Vapor Sound..Breeze or Stiff Breeze. Ryan the owner has used those 2 speakers as his intro into his speakers..he breaks even with all the money he puts into the speakers.